Q I have been recommending your arginine formulations to my nondiabetic patients. Your labels state that arginine is contraindicated for diabetics. Why is that so? It appears that there is much evidence supporting its use for diabetes.

MICHAEL, Las Vegas

A Arginine can have a wide variety of beneficial effects for diabetics.1-10 In large enough amounts, however, it can stimulate the release of growth hormone, and growth hormone can increase the level of a protein called insulinlike growth factor-I (IGF-I), which could interfere with insulin’s efficacy in the body. For those with diabetes or insulin resistance, therefore, I recommend working with a qualified physician when using arginine.